<?php
   class Common{
      public static function echoArray($arr){
         if(is_array($arr)){
            echo '<pre>';
            print_r($arr);
            echo '</pre>';
         }else{
            echo '<pre>';
            var_dump($arr);
            echo '</pre>';
         }
      }
      public static function formatNumber($number,$step = '.'){
         return number_format($number,0,',',$step);  
      }
      public static function goBack(){
         echo '<script>window.history.back();</script>';
      }
   }
   
?>